iOS 6.1.3 was not release 8 hours ago when the reply was made. The discussion now needs to take a different track.
It is not now possible for jailbreakers to restore a jailbreakable version of iOS on iPad 2, 3, or 4.
@icebun - I think I may have misinterpreted the question you asked initially.
If you were asking whether you can use "restore from backup" in iTunes without removing your jailbreak, then the answer is YES you can. Even with the release of 6.1.3, that makes no difference. You can restore a personal backup at any time without affecting the version of IOS installed.
What confused me was the title, which asked "will restoring from iTunes remove the jailbreak on IOS 6.1.2". An iTunes restore will normally refer to a full restore which will wipe all the content from the iPad. It is normally NOT related to restoring your backup.
It is one of the very confusing things about Apples use of the word "restore" in context of the iPad.
1) iTunes Restore - Wipes the iPad and restores a fresh copy of the latest version of IOS on the device (wiping a jailbreak at the same time).
2) Restore from Backup using iTunes - Will put your apps, media, settings, documents, photos, etc. back to a previous backup state - This does not interfere with the jailbreak or the version of IOS you have installed, and can be done at any time (assuming you want to go back in time for some reason).
So if, as I suspect, you have a freshly jailbroken device, then you are safe to "Restore from Backup" using iTunes in order to get all your apps, etc. back onto your device.
Apologies for the confusion.